The American ASTM natural stone classification criteria
 
Authority as the nation's standard of decoration materials - American Society for Testing Materials (ASTM),  made a more comprehensive definition and classification of the various types of natural stone formulated strict technical standards and specifications, and also won the agreef with and the adopted  by China, the EU, Japan and  the vast majority of the world's countries. like China limestone, sandstone , the material standards identified Stone Quality Inspection Center of National Building Materials Industry directly to the American ASTM standard detection .
 
Currently, the American Society of Testing and Materials natural decorative stone into Granite, limestone, marble sandstone, Slateand other stone six categories, ( detailed in ASTM C119 standards).
 
A. GraniteDefinition: granular igneous, color usually from pink to light gray or dark gray, mainly by quartz and feldspar, and accompanied by a small number of black mineral particles of uniform texture, some were gneiss or porphyry structure.
 
II. Limestone
Definition: mainly composed of calcium carbonate, magnesium or calcium carbonate (Baiyun mineral), or a mixture of the two minerals are composed of a sedimentary rock, and have the following in the commercial - gray clastic rocks, shells limestones, dolomites , microcrystalline limestone the, 麺 limestone, recrystallized limestone, travertine.
Performance Category:
The low density limestone, density in 1.76-2.16g/cm3
The limestone, density, medium density range in 1.76-2.56g/cm3.
High-density limestone, density 2.56g/cm3 more.
 
III. Marble
Definition: This class stone must can be polished, larger changes in composition and structure type, ranging from pure carbonate to a very low content of carbonate rock, collectively referred to as commercial marble. Most of its own patterns or veining crystal particle size from aphanitic to a diameter of 5 mm.
Category:
Business is divided into calcite marble, dolomite,marble, onyx striped marble, serpentine marble, travertine marble, etc..
Calcite marble: mainly composed of calcite, a unique crystal structure due to recrystallization.
Dolomite marble: mainly by the dolomite composition forming a crystal structure, after the deterioration of the high temperature and pressure.
Serpentine marble: mainly composed of serpentine (magnesium silicate hydrate), green or dark green, accompanied by dolomite, calcite or magnesite veins.
The travertine marble: porous layered structure, with some calcite crystals travertine.
 
IV. Sandstone
Definition: mainly by minerals and rock particles (particle size of 0.06-2mm) composition and containing more than 60% silica, a class of sedimentary rock. It has a multi-void structure of silica, iron oxide, carbonate or clay condensed.
Category:
The business is divided into the blue-gray sandstone, brown sandstone, quartz sandstone, quartzite, gravel, siltstone is.
Sandstone: silica content of 60-90%.
Is quartz: silica content of 90-95%.
Quartzite: the silica content of more than 95%.
 
V. Slate
Definition: belonging to the microcrystalline metamorphic rocks, most often derived from shale, mainly composed of mica, Asia polyoxometalates and quartz. Slate contains mica minerals are approximately parallel to the trend, split along the bedding plane to form a thin, hard slate.
 
Six. Other stone
Level stone semi-precious stones, such as jade, which is sometimes used as a decorative stone. General amount is not large, play a decorative role. Include alabaster, greenstone, schist, soapstone.